Barbed sutures are generally made of the same materials as conventional sutures and offer several advantages for closing wounds compared with conventional sutures. A barbed suture includes an elongated body that has one or more spaced barbs, that project from the surface of the suture body along the body length. The barbs are arranged to allow passage of the barbed suture in one direction through tissue but resist movement of the barbed suture in the opposite direction. Thus, one advantage of barbed sutures has been the provision of a non-slip attribute.
Barbed sutures are known for use in cosmetic, laparoscopic and endoscopic procedures. The number of barbs called for on a particular suture may be influenced by the size of the wound and the strength required to hold the wound closed. Like a conventional suture, a barbed suture may be inserted into tissue using a surgical needle.
In some circumstances, a random configuration of barbs on the exterior surface of the suture is preferred to achieve optimal wound closure holding for the particular wound. However, in other circumstances, where the wound or tissue repair needed is relatively small, a reduced number of barbs may be desired. In other circumstances, a two way barbed suture is desirable where the barbs permit passing of the suture in one direction over a portion of the suture and barbs permitting passing of the suture in a second direction over another portion of the suture to perform a tight closing stitch.
Various methods of forming barbs on sutures have been proposed such as mechanical cutting, laser cutting, injection molding, stamping, extrusion and the like. However, such methods may be difficult or costly to achieve the desired result with respect to getting the arrangement of barbs in a configuration needed for the appropriate procedure and for doing so in an efficient cost effective manner.
Conventional cutting methods of forming barbs have significant drawbacks in their ability to maintain sharpness, move rapidly, part cost and have slow manufacturing cycle time.
Accordingly, there is a continuing need for methods of forming barbs on a suture that are less difficult, more effective and economical. There is also a continuing need for methods which are able to vary the size of the barbs, the location and the depth, as well as a need for determining the amount of the barbs needed on a suture for the type of tissue to be repaired.